1. Field of the Invention
The present invention relates to agricultural harvesters such as combines, and, more particularly, to auger assemblies used in such combines.
2. Description of the Related Art
An agricultural harvester known as a “combine” is historically termed as such because it combines multiple harvesting functions with a single harvesting unit, such as picking, threshing, separating and cleaning. A combine includes a header which removes the crop from a field, and a feeder housing which transports the crop matter into a threshing rotor. The threshing rotor rotates within a perforated housing, which may be in the form of adjustable concaves and performs a threshing operation on the crop to remove the grain. Once the grain is threshed it falls through perforations in the concaves onto a grain pan. From the grain pan the grain is cleaned using a cleaning system, and is then transported to a grain tank onboard the combine. When the grain tank becomes full, the combine is positioned adjacent a vehicle into which the grain is to be unloaded, such as a semi-trailer, gravity box, straight truck, or the like; and an unloading system on the combine is actuated to transfer the grain into the vehicle.
Typical unloading systems for combines involve unloading augers that are formed from first and second tubes with rotatable augers inside that can be actuated to move grain longitudinally through the tubes. The tubes are pivoted to the combine so that they may be displaced laterally relative to the movement of the combine to an unload position in which grain is deposited in a wagon or other vehicle for transport. When the unloading function is completed, the auger tubes are retracted to a fold position in which the first auger tube is generally parallel to the longitudinal axis of the combine and the second auger tube is bent to an angle so that its free end is maintained within the overall configuration of the combine.
The auger tubes are displaced between the fold and unload position by actuators, one of which is on the first tube connected to the combine and the other to swing the second auger tube to its unload position. The construction of the mechanism for translating the movement of the actuator to the load and unload position typically involves an over center configuration in which the load is taken off the actuator when the tubes are in the fold or unload positions. Because it is frequently necessary to employ auger tubes of different lengths, the fold angle is different depending upon the length of the tubes. With current actuation systems, the need to employ multiple angles results in a mechanism that does not take the load off the actuators all potential fold positions.
Accordingly what is needed in the art is an auger tube assembly in which the load is maintained off the actuator in multiple positions.